What ROS distribution with OpenCV 4

edit

Hi, I am completely new with ROS, but I want to start using ROS and integrate it with OpenCV 4 (C++/python). The simple approach I am thinking is to create a node reading from a camera and creating another node to process it (I have doubts in connection with creating two nodes and a topic, or creating a service, ..).

At least, I want OpenCV 4 capabilities to process the frames in one node (e.g. face detection, apply pre-trained deep learning models available in OpenCV, among others - but starting with a very simple processing algorithm).

My question is: What ROS distribution is necessary/recommended for OpenCV 4 compatibility? I am reading this (http://wiki.ros.org/Distributions) but only appears OpenCV 3.

Thanks in advance